fix: TBP for the invalid usage of GH workflow_dispatch action (#36429)

## Description
PR to fix invalid usage of workflow_dispatch action.

## Automation

/ok-to-test tags=""

### 🔍 Cypress test results
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> [!CAUTION]  
> If you modify the content in this section, you are likely to disrupt
the CI result for your PR.

<!-- end of auto-generated comment: Cypress test results  -->


## Communication
Should the DevRel and Marketing teams inform users about this change?
- [ ] Yes
- [x] No


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Chores**
- Updated workflow configuration for improved accuracy in invoking
processes based on the `release` branch.
	- Specified the runner environment to enhance build reliability.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

.github/workflows/test-build-docker-image.yml

@@ -62,10 +62,13 @@ jobs:
   invoke-tbp-workflow-for-pg:
     needs: [setup]
     if: github.event_name != 'push' && github.ref == 'refs/heads/release'
-    uses: benc-uk/workflow-dispatch@v1
-    with:
-      workflow: test-build-docker-image.yml
-      inputs: '{ "ref": "pg"}'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Trigger TBP on pg branch
+        uses: benc-uk/workflow-dispatch@v1
+        with:
+          workflow: test-build-docker-image.yml
+          inputs: '{ "ref": "refs/heads/pg"}'
 
   server-build:
     needs: [setup]